Different types of APIs must follow specific protocols. Which provides rules
for API calls. Specifying accepted data types and commands. These are the types
of API protocols:
1. REST - REST is resource based. REST focuses on resources, actual
data but it keeps verbs to a minimum, using HTTP methods:
Get
Put
Post
Delete
REST also proposes constraints, i.e., limits that should not be exceeded.
The client-server autonomy constraint comes first. REST mandates that clients
and servers are unconcerned with one another's internal parts. So long as the
interface between the server and the client remains unchanged. They can go
through a variety of changes without it affecting their contact. However, the
user interface must remain intact. As a result, there is more versatility.
A uniform interface is another constraint. This entails a
consistent presentation of services to customers, as well as constant guidance
across the system. There is a single naming convention, a single data format,
and a single endpoint format. An endpoint is the resource's actual address. It
has URIs and an HTTP method for operating the resource. Get to retrieve,
post to build, put to update, and delete to erase a resource
are the most common.
Developers can understand an API's logic once and then extend it to other APIs
using a uniform interface. Behind a server, a group of other servers may be hidden.
These services assist in the creation of a client response. However, a client
contacts this specific communication server, which aggregates the response for
the client.
As a result, the customer is unconcerned with what's going on
behind the scenes.
It just knows how to handle the message returned by a communication
server. On the server-side, this allows for more scalability.
Stateless interactions are a REST constraint that treats each
request as unique. The server does not keep any information from previous sessions.
Caching, HTTP caching in particular, is another constraint that REST APIs employ.
As a result, clients can keep their content, and the server's load is reduced. The
final constraint of REST is code on demand, which is seldom used. A hidden chat in a
messenger to encrypt communication is a good use for code on demand.
2. SOAP - SOAP or simple object access protocol is a well-known protocol
that works similarly to REST. It's designed to be extensible and self-contained. An
envelope tag is used to frame a SOAP message. An envelope is a root element
of every soap message, starting and ending it. Then there's a header, which is an
optional feature that can be filled out with application-specific information or
additional message processing specifications.
SOAP or simple object access protocol is a well-known protocol that works
similarly to REST. It's designed to be extensible and self-contained. An envelope
tag is used to frame a SOAP message. An envelope is a root element of every soap
message, starting and ending it. Then there's a header, which is an optional feature
that can be filled out with application-specific information or additional message
processing specifications. The request for the receiver is contained in the body.
The fail element will be included in the response if request processing fails to
define the problem that occurred. The SOAP WS-security extension encrypts and locks
a message. They make it possible for a receiver with a security token to authenticate
and gain access to the body. SOAP messages may be chained together to keep the server
informed about previous requests. Storing all of the obtained data is taxing on the
server, but it is needed for complex transactions when several people are involved.
A server and a client are also tightly coupled in SOAP. If you want to alter a
message's properties, you'll need to make adjustments to both the server and
the client.
3. RPC - RPC, or remote procedure call, was the first and most basic
type of API. A local client sends commands to a remote server in this direct
interaction. When both clients, such as an application and a server, use different
call parameters, they must be translated so that they can be understood on the
other side. Stubs, or dedicated pieces of code, are used to convert these
parameters. A client stub transforms parameters used in a function call when a
client calls a server via an RPC API. After the server stub converts the client's
result back, the client stub deconverts them on its side and executes the function.
Since the 1980s, the RPC pattern has been used. It began with XML and progressed to
JSON-based versions. Google released GRPC, a general-purpose RPC, in 2015. Today,
large systems such as Facebook's apache thrift and Twitch's twerp depend solely on
GRPC for internal microservices communication.
As services exchange tons of calls per day, it takes a really high-performance
API to optimize the network layer. And RPC style, with its short, lightweight
messages, makes it easy on the network.
4. GraphQL - In 2015, Facebook grew tired of using REST to fetch data,
so they created GraphQL, a new API syntax. GraphQL, in contrast to the others,
sends a single precise request that receives an all-encompassing response. There
are several endpoints in REST, and they all return the same data, so a client must
mix and match those endpoints to get the details it needs for its current request.
Clients can configure endpoints in GraphQL. They do this by employing a schema.
It gives a client an overview of how the server's data is organized and what
resources are available, their relationships, and the fields that each resource
contains. A client would be able to formulate a question that asks the server no
more and no less in this manner. Although it is a time-consuming operation,
back-end developers define a schema upfront. Making a single question to the
server pays off later. GraphQL optimizes the payload in a way that is particularly
appealing to mobile users. GraphQL is quickly becoming the standard for
mobile APIs.